A non-volatile memory device such as a flash memory not only has excellent data retention characteristics, and but also has low power consumption and high impact-resistant characteristics in comparison to a hard disk. In particular, a flash memory having a NOR structure allows high-speed random access and thus is used to store codes, and a flash memory having a NAND structure has a high level of integration and allows a page operation, and thus is generally used to store data. The above-described flash memory is required to sequentially exchange data with a host according to a product or an interface.
A NAND cell array may include a plurality of blocks, and each block may have a matrix structure of rows referred to as word-lines, and columns referred to as bit-lines.
In general, three types of operations, for example, erase, program, and read, may be performed on a NAND cell. An erase operation may be performed in units of a block or a word-line. When a program operation is performed, all NAND cells in one word-line should be programmed at the same time.